Function stripPort

packages/server/src/middleware/hostnames.ts:86–104

(host: string)

 *     lowercased as-is — there is no unambiguous port to strip.
 */
export function stripPort(host: string): string {
  if (host.startsWith('[')) {
    const end = host.indexOf(']');
    return (end === -1 ? host : host.slice(0, end + 1)).toLowerCase();
  }
  const firstColon = host.indexOf(':');
  if (firstColon === -1) {
    return host.toLowerCase();
  }
  const lastColon = host.lastIndexOf(':');
  if (firstColon === lastColon) {
    const after = host.slice(lastColon + 1);
    if (after.length > 0 && /^\d+$/.test(after)) {
      return host.slice(0, lastColon).toLowerCase();
    }
  }
  // Multiple colons (bare IPv6) or a non-digit suffix — no port to strip.
  return host.toLowerCase();
}

export function formatHostErrorMessage(host: string | undefined): string {
  const normalizedHost = host === undefined || host.length === 0 ? undefined : stripPort(host);